Same reason it should be okay to get mad at Microsoft for viruses, at Facebook for gathering and abusing data on people etc. etc.
It's not about the capability, it's about the irresponsibility of these parties who reasonably know about this stuff and these possibilities, and yet push/sell their tech anyway without taking into account the harm.
I agree with the author on the defamation. But if they're mad about the government's ability to determine fact from fiction for coronavirus vaccines or their preferred libertarian information, what do they want to happen here?
It's not about the capability, it's about the irresponsibility of these parties who reasonably know about this stuff and these possibilities, and yet push/sell their tech anyway without taking into account the harm.